what steps can i take to take my music theory knowledge from intermediate to advanced

A lot of people will recommend books and videos and classes. I say osmosis. Hang around making music and talking about music with people who know more music theory than you. If you can't physically do that, then use forums like this one: share music and talk about it from a theory perspective.

The bottom line is, if you don't absorb knowledge of music theory at the same time that you're making and listening to music, it won't (or, I guess, it might not) fit together naturally and you won't be able to apply it in any meaningful way.

Which gets me to a question: what is your goal for learning music theory? Why do you think you need it?